1. Field of the Invention
This invention is directed to novel collagen/cytotoxic drug compositions. The compositions described herein possess surprising and unexpectedly enhanced drug retention at the site of injection as compared to collagen/cytotoxic drug compositions heretofore disclosed in the art.
2. State of the Art
The treatment of many cellular disorders, for example, tumors, involves the use of cytotoxic drugs. These drugs exert their activity in a variety of ways, usually interfering with a cellular function essential for replication and/or viability of the cell. In many, if not most, instances, the cytotoxic drug is not specific for the unnatural cell, but rather tends to exert its effectiveness due to the more rapid proliferation of the abnormal cell, as compared to normal cells. While many organs of the body of a mammalian host regenerate cells rather slowly, there are also other organs, particularly bone marrow, which involve rapid proliferation of stem cells. Therefore, the cytotoxic agents not only can detrimentally affect the slowly regenerating cells, but also have a particularly pernicious effect on the immune system.
One method to target cytotoxic drug activity toward abnormal cells is set forth by Luck and Brown, Reissue U.S. Pat. No. RE 33,375, which describes treatment of cellular disorders involving abnormal solid cellular growths by introduction of cytotoxic agents dispersed in a physiologically acceptable proteinaceous matrix, such as collagen, into the solid cellular growth or area of an existing or removed solid cellular growth. This patent discloses that the methods described therein provide enhanced effectiveness of the drug on the solid cellular growth with reduced cytotoxic effects on cells distant from the site of introduction. The disclosure of this patent is incorporated herein by reference in its entirety.
While effective against solid cellular growths, the physiological acceptable proteinaceous matrix prepared by Luck and Brown is optically opaque. If such a preparation was clear to translucent, it would be more pharmaceutically elegant.
Notwithstanding the benefits of the methods described by Luck, et al., further reductions in the cytotoxic effects on cells distant from the site of introduction would be particularly beneficial. Additionally, the preparation of a more pharmaceutically elegant composition would also be desirable.